Rough idle, won't rev past 1.5k rpm, and no start after VANOS clean on 2006 BMW E90 320i N46

[Micobe]

Salutations everyone, For anyone curious, I've been attempting to fix a BMW that we owned for almost 12 years. About three years ago (2022), it unexpectedly died, and my dad attempted to fix it but forgot. He parked it in our front yard, where it has remained for the last three years. I began working on it in October, but with my part-time job and school responsibilities, I don't have much spare time. Here are the components and fixes that I have applied thus far. Although the number on the body is 200k, the engine mileage is closer to 37k, because my uncle installed a new engine when it was previously owned by him.

Initial symptoms before to undertaking any task:
• Inactive
• Vibrations in the engine • Fluttering-like unstable RPMs
• Pressing the throttle completely causes it to not rev past approximately 1500 RPM. • Starting from scratch (different attempts)

After around five to eight minutes of running, the car would finally calm down, but it would still run and idle poorly.

Current tasks (in chronological order): • Fuel pump replaced
• Put in four brand-new spark plugs from Bosch performed a plug-and-unplug test on the coils • Took off the airbox, changed the air filter, and used WD-40 electrical contact cleaner to clean the MAF sensor.
• Took out the VANOS solenoids, cleaned them using WD-40 contact cleaner, and put them back where they came from.

The vehicle was operating (roughly, but running) before VANOS was cleaned.

Following your VANOS cleaning: • Cranks, but won't start, engine • Cranked normally at first, but after a few tries it started cranking more slowly; I suspect the battery was dying since the dash began to flutter as it was cranking very slowly, and finally it stopped cranking altogether.

Further details: • Although it has been removed, the battery was first run with the transit vent plugs still installed, even though it is just a couple months old. • A wall charger has been used to charge the battery. MAF was given ample time to air dry before being reinstalled; following the reinstallation, it ran smoothly. There are a few irrelevant codes that come up in the OBD scan, but nothing that specifically mentions VANOS. The VANOS connectors are correctly inserted. • Now I'm not entirely certain that this is the problem, but I cleaned the VANOS solenoids and, in my foolishness, didn't wait for them to dry before putting them back in. However, after doing some more research, I found that this might not be the case.

What are the questions? Can cleaning VANOS solenoids cause a complete lack of starting? Is it possible that the WD-40 contact cleaner completely ruined the VANOS solenoids? Now what am I supposed to do or verify?


Struggling to find the problem methodically while avoiding tossing parts at it. Please provide whatever guidance you can. If anyone is interested in seeing images or videos of the travel, I have chronicled it quite a bit. Just let me know!

[Liveek]

Shake the vanos solenoids once more after removing them. Are you perceiving a faint clattering noise? If they don't, they're in utter limbo.

Sludge can also accumulate at the vanos check valves, which are situated along the liner of the wheel arch on the passenger side.


Still, I think it's more of a mixing issue. Since the vehicle has been inactive for an extended period of time, numerous potential issues have accrued.

Do you know whether there are any hoover leaks? A frequent location for CCV pipe is behind the valve cover.
Damaged Diaphragm or Cover of Valve
Are the spark plug wells greasy in any way?
Check the plugs after letting the car sit overnight; do they seem wet or do you detect a strong petrol odour? In that case, perhaps injectors that are leaking.

Is there a way to see if it's running lean or rich with live value reporting?

[Micobe]

Good day, To start, I really appreciate your response; it's been really helpful.

In the event that the vanos solenoids become "totally stuck" without making a clattering sound, I will remove them and give them a good shake. Is there a way to fix them or will I need to purchase new ones?


Please provide some visual aid, such as a link, video, or image, so that I may see the vanos check valves as well. I'm still learning the ropes of auto repair, so I'm not that knowledgeable about this (haha).

When I reinstalled the air intake box, I thought I could hear air leaking, but 1) the engine is really loud and 2) I have no idea what to listen for, haha.
Can you provide another link that highlights the CCV pipe? Thank you so much; I will also conduct some research on my own.

The spark plugs were completely black and charred, yet they did not contain any oil. Im going to include a picture of spark plugs.

I believe I can run live values with my extremely capable mid-high-end obd scanner. I'll scan it and see what comes up if you could be more detailed.

And lastly, I want to express my deepest gratitude for all of your assistance.

[Liveek]

Just to clarify, was the engine change completed before or after the three-year period of inactivity? I'm rereading your message.

Are the plugs in question new or old?
If you could tell me what additional errors you're getting, that would be great.



In my opinion, the rough idling is not caused by the vanos solenoids. You might as well check if they are effective now that you've started down this path.

If the plunger inside the solenoids cannot be heard moving when shaken, it is recommended to replace them.

Locate the valves.

[Liveek]

 

[Liveek]

But now we're back to the original problem: mixing. Getting too much gas or air is either happening or the car is experiencing this problem.

Pull the plugs in the morning as instructed before starting the engine. Run a light down the holes that hold the spark plugs.look for signs of moisture on the piston tops. Verify that the outlets' tips are moist.


Indeed, injectors that are leaking.

Check the injectors; are they black or grey in colour? If they are grey, it means they are ancient, leaky index injectors. The housing of the more recent index 11 injectors is black.

Take the plug out of the maf sensor and turn the key to start the engine if everything seems OK. It probably is a hoover leak if it runs well.

The presence or absence of a hissing sound is proportional to the leak's size and location.

I have the N53, so I'm not entirely sure where the CCV pips are on the N46. However, I'm sure there are plenty of videos on YouTube that would help you out.

Before anything else, check the maf and plugs. Report back with your findings.

[Liveek]

An easy approach to check for a vacuum leak is to start the car while unplugging the MAF.

After that, is it more efficient?

[Seconsu]

It is recommended to remove any old gasoline and replace it with fresh before continuing with the issue discovery process, as the fuel will also become stale after three years of sitting.